Sensor elements for detecting at least one property of a gas in a measured-gas space are available. The present invention is explained below, with no limitation of further possible embodiments, substantially with reference to methods and apparatuses that serve for quantitative and/or qualitative detection of at least one gas component in a measured-gas space. The gas can be, for example, an exhaust gas of an internal combustion engine, in particular in the automotive sector; and the measured-gas space can be, for example, an exhaust section. Sensor elements for detecting at least one property of gas are described, for example, in Robert Bosch GmbH: Sensoren im Kraftfahrzeug [Sensors in motor vehicles], 1st ed. 2010, pp. 98-111 and pp. 160-165. These can be, in particular, exhaust gas sensors having a variety of tasks. Binary oxygen sensors, in particular for measuring an oxygen content of the exhaust gas in the vicinity of air ratio λ=1, broadband oxygen sensors for measurement in the vicinity of air ratio λ=1 and in rich and lean exhaust gas, exhaust temperature sensors, nitrogen oxide sensors, and particle sensors are described, for example.
Exhaust gas sensors are operated in a vehicle, for example, in particular with an activation system, for example with a control unit. For this, the activation system, in particular the activation unit, has in particular a hardware module. The hardware module controls, for example, components of the exhaust gas sensor, in particular electrodes and/or heaters of the sensor element, in particular of the exhaust gas sensor.
This is done generally, depending on the complexity of the sensor element, for example using discrete electronic components, for example in the case of a binary sensor, and/or by way of discretely connected integrated electronic components, for example in the case of broadband lambda sensors or other exhaust gas sensors.
The heater can be operated, for example, on the one hand by (in particular) continuous application of a battery voltage to a vehicle ground, for example through a relay, on the other hand, for example, by cycled, in particular pulse width modulated switching of the battery voltage using a semiconductor switch, for example a “low-side” FET and/or a heater output stage, to vehicle ground. The heater output stage can be, for example, a discrete component in the activation system, in particular in the control unit, or can be contained in a multiple module. A multiple module of this kind can have in particular, besides one or more output-stage channels, further functions such as voltage supply and/or current supply and/or CAN communication and/or other functions.
The hardware module, in particular in the activation system, can be activated by a microcontroller of the activation system and in particular by the software contained therein, the so-called “hardware capsule.” This software can activate the sensor element if applicable via a probe ASIC and/or can activate the heater and/or can evaluate a probe signal and/or can perform correction and/or calibration functions and/or can carry out diagnoses, and/or can deliver the probe signal to, for example, downstream software functions of the exhaust gas post-processing system.
Methods and apparatuses for avoiding incorrect operation of sensor elements, in particular exhaust gas probes, are, for example, desired. An activation system, in particular a probe activation system, with, e.g., incorrect heating voltage and/or pump voltage can result, in particular, in corruptions and/or in destruction of the sensor element. Conventional actions, in particular conventional methods, are limited in particular to a configuration of the plug connection between the sensor element, for example the exhaust gas probe, and the activation system (the control unit). Methods are available, for example, that function on the “poka-yoke” principle, for example using a “plug socket,” in particular by conformation and/or coloring of, for example, a plug and/or by plug coding using at least one chip and/or at least one barcode.
Conventional methods are available, for example, for recognition of the sensor element, in particular of a sensor chip, by a shop testing unit. In a repair shop environment it is generally impossible, or possible only with difficulty, to ascertain the sensor type, in particular of the sensor element. For example, the shop testing unit in a first step can recognize, in particular independently, the sensor type; in a second step, for example, the shop testing unit can carry out a test program, in particular with no need for an operator, for example a mechanic, to input a probe type, for example a sensor type. It is thus possible to ensure, for example, that the test program and/or test parameters that is/are correct in particular for the respective sensor type can be used. It is thereby possible, for example, to reduce a number of incorrect diagnoses; for example, it is possible to prevent an intact sensor element from being recognized, in particular incorrectly, as defective.
A method and an apparatus that make possible in particular recognition of the probe type and/or of the sensor type, in particular of the sensor element, particularly preferably of the exhaust gas probe, and/or recognition of another property of, for example, an activation system, for example in a motor vehicle, would therefore be desirable.